Many are up for sale (4)

I believe the answer is:
lots
This could be a double definition.
'many' is the first definition.
(lots of something)
'up for sale' is the second definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'are' acts as a link.
Can you help me to learn more?
(Other definitions for lots that I've seen before include "Great quantities" , "Loads" , "Units sold at auctions - plenty of them" , "Large numbers at auction" , "a crowd?" .)
